/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package com.snail.utils;

import java.util.HashMap;

public class HTMLDecoder {

    public static final HashMap charTable;

    public static String decode(String s) {
        String t;
        Character ch;
        int tmpPos, i;
        int maxPos = s.length();
        StringBuffer sb = new StringBuffer(maxPos);
        int curPos = 0;
        while (curPos < maxPos) {
            char c = s.charAt(curPos++);
            if (c == '&') {
                tmpPos = curPos;
                if (tmpPos < maxPos) {
                    char d = s.charAt(tmpPos++);
                    if (d == '#') {
                        if (tmpPos < maxPos) {
                            d = s.charAt(tmpPos++);
                            if ((d == 'x') || (d == 'X')) {
                                if (tmpPos < maxPos) {
                                    d = s.charAt(tmpPos++);
                                    if (isHexDigit(d)) {
                                        while (tmpPos < maxPos) {
                                            d = s.charAt(tmpPos++);
                                            if (!isHexDigit(d)) {
                                                if (d == ';') {
                                                    t
                                                            = s.substring(
                                                                    curPos + 2,
                                                                    tmpPos - 1);
                                                    try {
                                                        i
                                                                = Integer.parseInt(
                                                                        t,
                                                                        16);
                                                        if ((i >= 0)
                                                                && (i < 65536)) {
                                                            c = (char) i;
                                                            curPos = tmpPos;
                                                        }
                                                    } catch (NumberFormatException e) {
                                                    }
                                                }
                                                break;
                                            }
                                        }
                                    }
                                }
                            } else if (isDigit(d)) {
                                while (tmpPos < maxPos) {
                                    d = s.charAt(tmpPos++);
                                    if (!isDigit(d)) {
                                        if (d == ';') {
                                            t
                                                    = s.substring(
                                                            curPos + 1,
                                                            tmpPos - 1);
                                            try {
                                                i = Integer.parseInt(t);
                                                if ((i >= 0) && (i < 65536)) {
                                                    c = (char) i;
                                                    curPos = tmpPos;
                                                }
                                            } catch (NumberFormatException e) {
                                            }
                                        }
                                        break;
                                    }
                                }
                            }
                        }
                    } else if (isLetter(d)) {
                        while (tmpPos < maxPos) {
                            d = s.charAt(tmpPos++);
                            if (!isLetterOrDigit(d)) {
                                if (d == ';') {
                                    t = s.substring(curPos, tmpPos - 1);
                                    ch = (Character) charTable.get(t);
                                    if (ch != null) {
                                        c = ch.charValue();
                                        curPos = tmpPos;
                                    }
                                }
                                break;
                            }
                        }
                    }
                }
            }
            sb.append(c);
        }
        return sb.toString();
    }

    private static boolean isLetterOrDigit(char c) {
        return isLetter(c) || isDigit(c);
    }

    private static boolean isHexDigit(char c) {
        return isHexLetter(c) || isDigit(c);
    }

    private static boolean isLetter(char c) {
        return ((c >= 'a') && (c <= 'z')) || ((c >= 'A') && (c <= 'Z'));
    }

    private static boolean isHexLetter(char c) {
        return ((c >= 'a') && (c <= 'f')) || ((c >= 'A') && (c <= 'F'));
    }

    private static boolean isDigit(char c) {
        return (c >= '0') && (c <= '9');
    }

    public static String compact(String s) {
        int maxPos = s.length();
        StringBuffer sb = new StringBuffer(maxPos);
        int curPos = 0;
        while (curPos < maxPos) {
            char c = s.charAt(curPos++);
            if (isWhitespace(c)) {
                while ((curPos < maxPos) && isWhitespace(s.charAt(curPos))) {
                    curPos++;
                }
                c = '\u0020';
            }
            sb.append(c);
        }
        return sb.toString();
    }

    // HTML is very particular about what constitutes white space. 

    public static boolean isWhitespace(char ch) {
        return (ch == '\u0020')
                || (ch == '\r')
                || (ch == '\n')
                || (ch == '\u0009')
                || (ch == '\u000c')
                || (ch == '\u200b');
    }

    static {
        charTable = new HashMap();
        charTable.put("quot", new Character((char) 34));
        charTable.put("amp", new Character((char) 38));
        charTable.put("apos", new Character((char) 39));
        charTable.put("lt", new Character((char) 60));
        charTable.put("gt", new Character((char) 62));
        charTable.put("nbsp", new Character((char) 160));
        charTable.put("iexcl", new Character((char) 161));
        charTable.put("cent", new Character((char) 162));
        charTable.put("pound", new Character((char) 163));
        charTable.put("curren", new Character((char) 164));
        charTable.put("yen", new Character((char) 165));
        charTable.put("brvbar", new Character((char) 166));
        charTable.put("sect", new Character((char) 167));
        charTable.put("uml", new Character((char) 168));
        charTable.put("copy", new Character((char) 169));
        charTable.put("ordf", new Character((char) 170));
        charTable.put("laquo", new Character((char) 171));
        charTable.put("not", new Character((char) 172));
        charTable.put("shy", new Character((char) 173));
        charTable.put("reg", new Character((char) 174));
        charTable.put("macr", new Character((char) 175));
        charTable.put("deg", new Character((char) 176));
        charTable.put("plusmn", new Character((char) 177));
        charTable.put("sup2", new Character((char) 178));
        charTable.put("sup3", new Character((char) 179));
        charTable.put("acute", new Character((char) 180));
        charTable.put("micro", new Character((char) 181));
        charTable.put("para", new Character((char) 182));
        charTable.put("middot", new Character((char) 183));
        charTable.put("cedil", new Character((char) 184));
        charTable.put("sup1", new Character((char) 185));
        charTable.put("ordm", new Character((char) 186));
        charTable.put("raquo", new Character((char) 187));
        charTable.put("frac14", new Character((char) 188));
        charTable.put("frac12", new Character((char) 189));
        charTable.put("frac34", new Character((char) 190));
        charTable.put("iquest", new Character((char) 191));
        charTable.put("Agrave", new Character((char) 192));
        charTable.put("Aacute", new Character((char) 193));
        charTable.put("Acirc", new Character((char) 194));
        charTable.put("Atilde", new Character((char) 195));
        charTable.put("Auml", new Character((char) 196));
        charTable.put("Aring", new Character((char) 197));
        charTable.put("AElig", new Character((char) 198));
        charTable.put("Ccedil", new Character((char) 199));
        charTable.put("Egrave", new Character((char) 200));
        charTable.put("Eacute", new Character((char) 201));
        charTable.put("Ecirc", new Character((char) 202));
        charTable.put("Euml", new Character((char) 203));
        charTable.put("Igrave", new Character((char) 204));
        charTable.put("Iacute", new Character((char) 205));
        charTable.put("Icirc", new Character((char) 206));
        charTable.put("Iuml", new Character((char) 207));
        charTable.put("ETH", new Character((char) 208));
        charTable.put("Ntilde", new Character((char) 209));
        charTable.put("Ograve", new Character((char) 210));
        charTable.put("Oacute", new Character((char) 211));
        charTable.put("Ocirc", new Character((char) 212));
        charTable.put("Otilde", new Character((char) 213));
        charTable.put("Ouml", new Character((char) 214));
        charTable.put("times", new Character((char) 215));
        charTable.put("Oslash", new Character((char) 216));
        charTable.put("Ugrave", new Character((char) 217));
        charTable.put("Uacute", new Character((char) 218));
        charTable.put("Ucirc", new Character((char) 219));
        charTable.put("Uuml", new Character((char) 220));
        charTable.put("Yacute", new Character((char) 221));
        charTable.put("THORN", new Character((char) 222));
        charTable.put("szlig", new Character((char) 223));
        charTable.put("agrave", new Character((char) 224));
        charTable.put("aacute", new Character((char) 225));
        charTable.put("acirc", new Character((char) 226));
        charTable.put("atilde", new Character((char) 227));
        charTable.put("auml", new Character((char) 228));
        charTable.put("aring", new Character((char) 229));
        charTable.put("aelig", new Character((char) 230));
        charTable.put("ccedil", new Character((char) 231));
        charTable.put("egrave", new Character((char) 232));
        charTable.put("eacute", new Character((char) 233));
        charTable.put("ecirc", new Character((char) 234));
        charTable.put("euml", new Character((char) 235));
        charTable.put("igrave", new Character((char) 236));
        charTable.put("iacute", new Character((char) 237));
        charTable.put("icirc", new Character((char) 238));
        charTable.put("iuml", new Character((char) 239));
        charTable.put("eth", new Character((char) 240));
        charTable.put("ntilde", new Character((char) 241));
        charTable.put("ograve", new Character((char) 242));
        charTable.put("oacute", new Character((char) 243));
        charTable.put("ocirc", new Character((char) 244));
        charTable.put("otilde", new Character((char) 245));
        charTable.put("ouml", new Character((char) 246));
        charTable.put("divide", new Character((char) 247));
        charTable.put("oslash", new Character((char) 248));
        charTable.put("ugrave", new Character((char) 249));
        charTable.put("uacute", new Character((char) 250));
        charTable.put("ucirc", new Character((char) 251));
        charTable.put("uuml", new Character((char) 252));
        charTable.put("yacute", new Character((char) 253));
        charTable.put("thorn", new Character((char) 254));
        charTable.put("yuml", new Character((char) 255));
        charTable.put("OElig", new Character((char) 338));
        charTable.put("oelig", new Character((char) 339));
        charTable.put("Scaron", new Character((char) 352));
        charTable.put("scaron", new Character((char) 353));
        charTable.put("fnof", new Character((char) 402));
        charTable.put("circ", new Character((char) 710));
        charTable.put("tilde", new Character((char) 732));
        charTable.put("Alpha", new Character((char) 913));
        charTable.put("Beta", new Character((char) 914));
        charTable.put("Gamma", new Character((char) 915));
        charTable.put("Delta", new Character((char) 916));
        charTable.put("Epsilon", new Character((char) 917));
        charTable.put("Zeta", new Character((char) 918));
        charTable.put("Eta", new Character((char) 919));
        charTable.put("Theta", new Character((char) 920));
        charTable.put("Iota", new Character((char) 921));
        charTable.put("Kappa", new Character((char) 922));
        charTable.put("Lambda", new Character((char) 923));
        charTable.put("Mu", new Character((char) 924));
        charTable.put("Nu", new Character((char) 925));
        charTable.put("Xi", new Character((char) 926));
        charTable.put("Omicron", new Character((char) 927));
        charTable.put("i", new Character((char) 928));
        charTable.put("Rho", new Character((char) 929));
        charTable.put("Sigma", new Character((char) 931));
        charTable.put("Tau", new Character((char) 932));
        charTable.put("Upsilon", new Character((char) 933));
        charTable.put("hi", new Character((char) 934));
        charTable.put("Chi", new Character((char) 935));
        charTable.put("si", new Character((char) 936));
        charTable.put("Omega", new Character((char) 937));
        charTable.put("alpha", new Character((char) 945));
        charTable.put("beta", new Character((char) 946));
        charTable.put("gamma", new Character((char) 947));
        charTable.put("delta", new Character((char) 948));
        charTable.put("epsilon", new Character((char) 949));
        charTable.put("zeta", new Character((char) 950));
        charTable.put("eta", new Character((char) 951));
        charTable.put("theta", new Character((char) 952));
        charTable.put("iota", new Character((char) 953));
        charTable.put("kappa", new Character((char) 954));
        charTable.put("lambda", new Character((char) 955));
        charTable.put("mu", new Character((char) 956));
        charTable.put("nu", new Character((char) 957));
        charTable.put("xi", new Character((char) 958));
        charTable.put("omicron", new Character((char) 959));
        charTable.put("pi", new Character((char) 960));
        charTable.put("rho", new Character((char) 961));
        charTable.put("sigmaf", new Character((char) 962));
        charTable.put("sigma", new Character((char) 963));
        charTable.put("tau", new Character((char) 964));
        charTable.put("upsilon", new Character((char) 965));
        charTable.put("phi", new Character((char) 966));
        charTable.put("chi", new Character((char) 967));
        charTable.put("psi", new Character((char) 968));
        charTable.put("omega", new Character((char) 969));
        charTable.put("thetasym", new Character((char) 977));
        charTable.put("upsih", new Character((char) 978));
        charTable.put("piv", new Character((char) 982));
        charTable.put("ensp", new Character((char) 8194));
        charTable.put("emsp", new Character((char) 8195));
        charTable.put("thinsp", new Character((char) 8201));
        charTable.put("zwnj", new Character((char) 8204));
        charTable.put("zwj", new Character((char) 8205));
        charTable.put("lrm", new Character((char) 8206));
        charTable.put("rlm", new Character((char) 8207));
        charTable.put("ndash", new Character((char) 8211));
        charTable.put("mdash", new Character((char) 8212));
        charTable.put("lsquo", new Character((char) 8216));
        charTable.put("rsquo", new Character((char) 8217));
        charTable.put("sbquo", new Character((char) 8218));
        charTable.put("ldquo", new Character((char) 8220));
        charTable.put("rdquo", new Character((char) 8221));
        charTable.put("bdquo", new Character((char) 8222));
        charTable.put("dagger", new Character((char) 8224));
        charTable.put("Dagger", new Character((char) 8225));
        charTable.put("bull", new Character((char) 8226));
        charTable.put("hellip", new Character((char) 8230));
        charTable.put("permil", new Character((char) 8240));
        charTable.put("prime", new Character((char) 8242));
        charTable.put("rime", new Character((char) 8243));
        charTable.put("lsaquo", new Character((char) 8249));
        charTable.put("rsaquo", new Character((char) 8250));
        charTable.put("oline", new Character((char) 8254));
        charTable.put("frasl", new Character((char) 8260));
        charTable.put("euro", new Character((char) 8364));
        charTable.put("image", new Character((char) 8465));
        charTable.put("weierp", new Character((char) 8472));
        charTable.put("real", new Character((char) 8476));
        charTable.put("trade", new Character((char) 8482));
        charTable.put("alefsym", new Character((char) 8501));
        charTable.put("larr", new Character((char) 8592));
        charTable.put("uarr", new Character((char) 8593));
        charTable.put("rarr", new Character((char) 8594));
        charTable.put("darr", new Character((char) 8595));
        charTable.put("harr", new Character((char) 8596));
        charTable.put("crarr", new Character((char) 8629));
        charTable.put("lArr", new Character((char) 8656));
        charTable.put("uArr", new Character((char) 8657));
        charTable.put("rArr", new Character((char) 8658));
        charTable.put("dArr", new Character((char) 8659));
        charTable.put("hArr", new Character((char) 8660));
        charTable.put("forall", new Character((char) 8704));
        charTable.put("part", new Character((char) 8706));
        charTable.put("exist", new Character((char) 8707));
        charTable.put("empty", new Character((char) 8709));
        charTable.put("nabla", new Character((char) 8711));
        charTable.put("isin", new Character((char) 8712));
        charTable.put("notin", new Character((char) 8713));
        charTable.put("ni", new Character((char) 8715));
        charTable.put("prod", new Character((char) 8719));
        charTable.put("sum", new Character((char) 8721));
        charTable.put("minus", new Character((char) 8722));
        charTable.put("lowast", new Character((char) 8727));
        charTable.put("radic", new Character((char) 8730));
        charTable.put("prop", new Character((char) 8733));
        charTable.put("infin", new Character((char) 8734));
        charTable.put("ang", new Character((char) 8736));
        charTable.put("and", new Character((char) 8743));
        charTable.put("or", new Character((char) 8744));
        charTable.put("cap", new Character((char) 8745));
        charTable.put("cup", new Character((char) 8746));
        charTable.put("int", new Character((char) 8747));
        charTable.put("there4", new Character((char) 8756));
        charTable.put("sim", new Character((char) 8764));
        charTable.put("cong", new Character((char) 8773));
        charTable.put("asymp", new Character((char) 8776));
        charTable.put("ne", new Character((char) 8800));
        charTable.put("equiv", new Character((char) 8801));
        charTable.put("le", new Character((char) 8804));
        charTable.put("ge", new Character((char) 8805));
        charTable.put("sub", new Character((char) 8834));
        charTable.put("sup", new Character((char) 8835));
        charTable.put("nsub", new Character((char) 8836));
        charTable.put("sube", new Character((char) 8838));
        charTable.put("supe", new Character((char) 8839));
        charTable.put("oplus", new Character((char) 8853));
        charTable.put("otimes", new Character((char) 8855));
        charTable.put("perp", new Character((char) 8869));
        charTable.put("sdot", new Character((char) 8901));
        charTable.put("lceil", new Character((char) 8968));
        charTable.put("rceil", new Character((char) 8969));
        charTable.put("lfloor", new Character((char) 8970));
        charTable.put("rfloor", new Character((char) 8971));
        charTable.put("lang", new Character((char) 9001));
        charTable.put("rang", new Character((char) 9002));
        charTable.put("loz", new Character((char) 9674));
        charTable.put("spades", new Character((char) 9824));
        charTable.put("clubs", new Character((char) 9827));
        charTable.put("hearts", new Character((char) 9829));
        charTable.put("diams", new Character((char) 9830));
    }
}
